These are two different skills, and a good review uses both.
Description is what happened. What you saw, tasted, smelled, felt. It's sensory, specific, and as objective as possible.
"The octopus was charred on the outside, tender inside, served on a bed of romesco with a drizzle of olive oil. The char flavour was pronounced, smoky, with a slight bitterness at the edges. The romesco was nutty and sweet with a gentle heat."
Assessment is your evaluation. Did it work? Was it good? How good?
"The balance between the smoky char and the sweet romesco was excellent. Neither dominated. The octopus itself was perfectly cooked, yielding without being mushy. This was a dish with total clarity: three elements, each one right, nothing extra."
Description without assessment is a menu recitation. Assessment without description is an unsupported opinion. The combination is what makes a review worth reading.
The Order Matters
Lead with description, then assess. Show the reader what was on the plate before telling them what you thought about it. This builds trust. The reader can see that your assessment is grounded in specific observations, not just a gut feeling.
Compare:
Weak: "The steak was incredible. Perfectly cooked. Best I've had in Barcelona."
Strong: "The steak, a thick-cut entrecôte seared to a deep, even crust, arrived medium-rare as ordered. The interior was uniformly pink and warm throughout, no grey band. The seasoning was assertive: a generous crust of coarse salt and cracked pepper that held up against the richness of the meat. Simply one of the best-executed steaks I've had in the city."
The second version earns the superlative. The first just claims it.